1. Field of the Invention
The present invention related to a container for fluidal materials, and more particularly, to a container for fluidal materials readily collapsible to a flattened shape.
2. Description of the Prior Art
When a viscous fluidal material such as the modern printing ink is supplied from a container serving as a source of the material in a machine such as a printer, one of the important matters to be cared for is that the container is prepared to decrease its effective inside space volume according to discharge of the material from the container, because, otherwise, a smooth discharge of the material will soon be obstructed by a reversed pressure gradient applied to a discharge port of the container as a vacuum is generated in the container, provided that the container has a rigid construction. On the other hand, when the container has a flexible construction like a toothpaste tube, while a material is discharged from the container by a drawing action applied to a discharge port from the outside thereof, the discharge of the material will not be immediately obstructed, but it is highly probable that the drawing action applied to the discharge port soon contracts a lengthwise middle portion of the container before the drawing action is transmitted to the material in a rear portion of the container remote from the discharge port, so as finally completely to throttle the middle portion, thereby locking the material contained in the rear portion of the container to be no longer dischargeable regardless how strong the drawing action is.
In view of the above problems, in the art of the containers having a rigid construction, it has been proposed to construct the container as an assembly of a cylinder member and a piston member, the latter providing a bottom wall of the cylinder member movable along the axis thereof so as to decrease the effective inside space volume of the cylinder member according to a discharge of the material through a discharge port provided at an end of the cylinder member opposing the bottom wall provided by the piston member, as disclosed in Japanese Patent Laid-open Publications 59-37162 and 59-37163 and Japanese Utility Model Laid-open Publication 5-95878.
Further, under the recent concern about the conservation of nature, it has also been proposed to construct the containers for fluidal materials substantially by a film material in combination with a rigid case member, the latter serving as a means for providing the film-made configurationally unstable container with a firm configuration on one hand, while on the other hand serving as a means for supporting the film-made container from being throttled at a middle portion thereof when a fluidal material contained therein is discharged by a drawing action, particularly when the material is a viscous fluidal material, as disclosed in Japanese Utility Model Laid-open Publication 5-82858 and Japanese Utility Model Publication 2503067.
According to the Japanese Publication 5-82858, a container having an elongated body substantially made of a film material except a nozzle portion of a rigid construction, is housed in a rigid cylindrical case member, with the nozzle portion being fixed to the cylindrical case member, while the elongated film body is freely disposed in the cylindrical case member except a longitudinally middle portion thereof, at which the elongated film body is bonded to the case member, so that, when the fluidal material contained in the container is drawn out through the nozzle portion, a longitudinally half portion of the elongated film body remote from the nozzle portion is shifted toward the nozzle portion, so as to be finally turned over inside out, until the effective inside space of the container is finally almost completely canceled. When the container has been used, i.e. the material contained therein has been exhausted, the container is disassembled from the case member for disposal, while the case member is reused for a next new container through a process of inserting the container into the case member, and bonding the middle portion of the container to the case member.
According to the Japanese Utility Model 2503067, an elongated cylindrical container having a longitudinal half portion of a rigid construction and a longitudinal half portion of a flexible film bag construction is assembled with a nozzle member and an elongated cylindrical outer case member, such that the container is fixed to the nozzle member and the outer case member at an end of the rigid half portion remote from the flexible half portion coaxially disposed in the outer case member. When a fluidal material charged in the container is discharged therefrom by a pressure being applied to the outside of the container according to an introduction of a pressure medium into a chamber space formed between the container and the outer case member, the flexible half portion of the container is shifted into the rigid half portion thereof so to be finally turned over inside out, thereby canceling the effective inside space volume of the container. When the container has been used, the container is disassembled from the nozzle member and the outer case member for disposal.
In those above-mentioned prior arts, in order for the used container to be disposed at a minimum volume, a substantial work such as crushing the rigid container, disassembling the film-made container from the nozzle and the outer case member by breaking the bonding between the middle portion of the film-made container and the case member, or crushing the rigid half portion of the half film-made container, is required, all such works being highly liable to a contamination by the fluidal material such as ink.